摘要 |
<p>A conduction welding apparatus, a mandrel, and method for bonding abutted thermal plastic tubular end portions (55, 76) is particularly suitable for welding PFA. A folding weld head (22) embraces the abutted tubular end portions (55, 76) to be welded, each tubular end portion (76) including a flange (74) spaced from the surfaces to be joined. The weld head includes means for securing the flanges within the weld head and further includes bias means (277). The bias means (277) provide an inward axial bias on the adjoined tubular end portions when the tubular end portions (55, 76) are displaced axially outward from the weld head due to the expansion of the plastic during the weld process. The mandrel (136) comprises a first core portion (320) and a second tubing contact portion (322) which are longitudinally movable relative to each other between a first conjoining configuration and a second removal configuration.</p> |